This invention relates to a fluorescent lamp conversion unit and, in particular, to a fluorescent lamp conversion unit for use in combination with a residential incandescent-type lamp fixture.
It is well known that a fluorescent lamp lighting system is more efficient than an incandescent lamp lighting system by a factor of three to four or more for equivalent illumination. In the past, however, fluorescent lamps have not been used for indoor residential lighting because of their poor color rendition compared to incandescent lighting. In recent years, however, fluorescent lamps are available with a color rendition comparable to incandescent. A number of conversion units have been disclosed to convert residential incandescent lighting fixtures to fluorescent. One such conversion unit is disclosed in U.S. Pat. No. 2,817,004 dated Dec. 17, 1957 issued to Baumgartener, et al. This patent discloses a combined adapter and holder for circular tubular fluorescent lamps. The combined adapter holder is mountable on existing light fixtures designed for incandescent lamps equipped for screw-type bases. The plane of the circular lamp envelope is parallel to the direction in which the screw-type socket opens.
Another such lamp conversion unit is disclosed in U.S. Pat. No. 2,697,777 dated Dec. 21, 1954, issued to Ercole Rosa. This patent describes a lamp adapter comprising a body including a first section and a second section. A circumferential ring on the body is secured to the first section and second section, thereby securing the first section to the second section. A plurality of circumferentially spaced grooves in the body and the plurality of brackets are included, the brackets have hooked portions detachably engaged in the grooves between the ring and the body. The brackets have accurate free-end portions adapted to support a circular fluorescent lamp.
In an article appearing in Lighting Design and Application, March 1976 Edition entitled "Conversion of Incandescent Lamp Sockets to Fluorescent in the Home Market" by E. A. Dale, a retrofit lighting system for converting incandescent fixtures to fluorescent is described. In FIG. 5 of the article is shown a solid-state ballast mounted within the periphery of the harp of a table lamp. A circular, tubular fluorescent is supported around the harp with its axis in the vertical plane.